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3F.15

Posted: Mon Nov 11, 2019 2:08 pm
by Rachel Yu 1G
Explain the difference between boiling points of AsF3 (63 C) and AsF5 (-53 C)

The Lewis structure for AsF3 has three As-F bonds and a lone pair whereas AsF5 had five As-F bonds. Is AsF3 a polar molecule because the As-F bonds create an unequal electron distribution with the presence of the lone pair, therefore having dipole interactions?

Re: 3F.15

Posted: Mon Nov 11, 2019 2:14 pm
by Parker Smith
I believe AsF3 is a non polar molecule. The highly electronegative fluorines will direct electron density around themselves, while the lone pair around the Arsenic non bonding domain will remain. Thus, the molecule will have a net negative charge surrounding its entirety.

Re: 3F.15

Posted: Tue Nov 12, 2019 5:47 pm
by Lauren Tanaka 1A
The boiling point of AsF3 will be higher than AsF5 since based on the Lewis structures you can determine that AsF3 is polar and AsF5 is nonpolar based on a net partial negative charge. Thus the dipole-dipole interactions for AsF3 will be stronger than AsF5 causing the boiling point to be higher.

Re: 3F.15

Posted: Tue Nov 12, 2019 5:52 pm
by dtolentino1E
a higher boiling point means that the elements in the molecule are highly attracted to each other i.e. the intermolecular forces are strong. because AsF3 is a polar molecule (F, as the most electromagnetic element, creates a dipole) the bonds between the elements are stronger and will take more energy to break apart (become a gas)